Niobium is a chemical element; it has symbol Nb (formerly columbium, Cb) and atomic number 41. It is a light grey, crystalline, and ductile transition...

element, along with vanadium and niobium, and it always occurs in geologic sources together with the chemically similar niobium, mainly in the mineral groups...

4.5 billion years for different isotopes, making them useful for dating the age of the Earth. The most common isotopes in natural uranium are uranium-238...

elements. At least 40 isotopes of hafnium have been observed, ranging in mass number from 153 to 192. The five stable isotopes have mass numbers ranging...

of isotopes of stable atoms. Thomson's device was a crude version of the instrument we now term a mass spectrometer. Neon has three stable isotopes: 20Ne...

isotopes are lutetium-174 with a half-life of 3.31 years, and lutetium-173 with a half-life of 1.37 years. All of the remaining radioactive isotopes have...

to power some spacecraft. Plutonium isotopes are expensive and inconvenient to separate, so particular isotopes are usually manufactured in specialized...

48 MeV of energy. The known isotopes of silicon range in mass number from 22 to 46. The most common decay mode of the isotopes with mass numbers lower than...

68 (erbium) isotopes, and the primary products after are element 70 (ytterbium) isotopes. Thulium-169 is thulium's only primordial isotope and is the only...

stable isotopes of potassium can be laser cooled and used to probe fundamental and technological problems in quantum physics. The two bosonic isotopes possess...

artificial isotopes of zirconium have been synthesized, ranging in atomic mass from 77 to 114. 93Zr is the longest-lived artificial isotope, with a half-life...

is generated. Radon isotopes are the immediate decay products of radium isotopes. The instability of 222Rn, its most stable isotope, makes radon one of...

Platinum also has 38 synthetic isotopes ranging in atomic mass from 165 to 208, making the total number of known isotopes 44. The least stable of these...

Because of the specificity of its uptake by the human body, radioactive isotopes of iodine can also be used to treat thyroid cancer. Iodine is also used...

142Nd are praseodymium isotopes, and the primary products after 142Nd are promethium isotopes. Four of the five stable isotopes are only observationally...

seven stable isotopes and two long-lived radioactive isotopes. More than 40 unstable xenon isotopes undergo radioactive decay, and the isotope ratios of...

of neptunium-237, these are the five most stable isotopes of radium. All other 27 known radium isotopes have half-lives under two hours, and the majority...

isotopes lighter than 141Pr is positron emission or electron capture to isotopes of cerium, while that of heavier isotopes is beta decay to isotopes of...

and iron, so as to recycle long-lived waste isotopes such as neptunium-237 into shorter-lived isotopes more useful as nuclear fuel. One neptunium-based...

years). Chromium isotopes are typically collocated (and compounded) with manganese isotopes. This circumstance is useful in isotope geology. Manganese-chromium...

isotopes, and the primary products after are erbium isotopes. Natural holmium consists of one primordial isotope, holmium-165; it is the only isotope...

The isotopes of ytterbium range from 149Yb to 187Yb. The primary decay mode of ytterbium isotopes lighter than the most abundant stable isotope, 174Yb...

However this metal was later recognized to be an alloy of the elements niobium and tantalum. The name "neptunium" was later given to the synthetic element...

always is to be mentioned. Naturally occurring lanthanum is made up of two isotopes, the stable 139 La and the primordial long-lived radioisotope 138 La. 139...

than 15 minutes. The isotopes of cobalt range in atomic weight from 50 u (50Co) to 73 u (73Co). The primary decay mode for isotopes with atomic mass unit...

ignite in air when finely divided. All known thorium isotopes are unstable. The most stable isotope, 232Th, has a half-life of 14.05 billion years, or about...

isotopes primarily undergo beta plus decay to isotopes of arsenic, and isotopes heavier than the stable isotopes undergo beta minus decay to isotopes...

possible to produce exotic helium isotopes, which rapidly decay into other substances. The shortest-lived heavy helium isotope is the unbound helium-10 with...

compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper. 63 Cu and 65 Cu are stable, with 63 Cu comprising approximately...

the vacuum polarization terms. Hydrogen has three naturally occurring isotopes, denoted 1 H, 2 H and 3 H. Other, highly unstable nuclei (4 H to 7 H) have...